Adaptations result from random mutations in the genes of organisms. Depending on the environment, these adaptations may be favorable or unfavorable. If an adaptation is favorable, it is selected by nature and, over time, more and more organisms in a population will have it. If the environment changes so much that the adaptations of a species are no longer enough for the species to survive, extinction will occur. Is the statement above correct? Why or why not?

Imagine a self-reactive t cell that has not undergone clonal deletion in the thymus (that is to say, it has escaped central tolerance). if it encounters self antigen in the absence of an infection or inflammation, what will happen to this self-reactive t cell? (select two answers) (a) the t cell undergoes clonal expansion. (b) the t cell gains effector functions. (c) the t cell undergoes apoptosis. (d) the t cell becomes activated. (e) the t cell becomes anergic.